223 vs 5.56 proof of no difference

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i have always believed that 223 and 5.56 are the same thing. there are other forums and people that i know that will darn near come to blows with you if you tell them they are the same. some have sold cases of ammo that was labeled 5.56 because they own a gun labeled .223 remington.

how can i prove it to these people, what is out there (on the internet, since they believe everything they read on wikipedia) to shut them up once and for all?

one forum moderator/ operator posted that it was true (in a very pissed off manner) because he ran the same load in military brass and commercial and the military was 3 fps faster. he proclaimed that the pressures were higher in 5.56 brass than 223 because of the 3 fps difference! wow, i want his chronograph, not only is it super accurate, it also measures pressure!
 
The 5.56 is loaded to higher chamber pressure than the 223. Usually the 5.56 has a longer throat and a looser chamber to assure proper function on full auto and dirty conditions.Tell them to check the Hornady 7th edition pages 150 through 158 they have the specs. and loads for both,the only diff is slug selection and load pressure.
 
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I don't think it will ever be laid to rest. Especially when prominent ammunition and firearm companies also play along.

Like I've said before.

Take a piece of 5.56 brass. Load a 50 gr bullet, standard primer, 23 grain charge of powder...

Take a piece of 223 brass, replicate the load.


Why would there be any differance? There isn't, because they're the same dang thing!!
 



5.56 is not loaded to higher pressures. Just measured differently. One is SAAMI and one NATO. that's all, folks...

Originally Posted By: BearThe 5.56 is loaded to higher chamber pressure than the 223. Usually the 5.56 has a longer throat and a looser chamber to assure proper function on full auto and dirty conditions.


SEE...more Internet nonsense. Except the military chambers are set-up a bit sloppy to accommodate field conditions. That part is true...
 
Originally Posted By: Luckygunner.comSummary: Velocities and pressures for 5.56 ammunition in a .223 barrel were not significantly higher than the same ammunition in a 5.56 barrel; in fact, they were in between the two 5.56 barrels. This doesn’t mean that your barrel will have the same results, and you should always be aware of pressure signs when holding metal objects containing 50-60,000psi of pressure only a few inches away from your face.

Here's the deal. Each and every chamber is different. It will act differently then an otherwise identical rifle right beside it. I've seen prim ers popped by a completely factory rifle with a .223 rem stamp on the barrel, shooting regular white box ammo. It happens. And as the article pointed out, 5.56 ammo CAN be loaded higher, but this is not all inclusive. It actually show where some 5.56 ammo is loaded lighter. Same can be said for .223 rem ammo. The Hornady superformance stuff has a bit more pop to it, versus standard, run of the mill 223 stuff.

Heck, a lot of us reload, and likely push to and past "recommended SAAMI specs" it happens. There are tons more variables then just headstamps.

IE; A normally ok load, sitting in the sun, or a hot chamber, suddenly pops primers or blows out extractors, etc. This happens all the time in PDog fields of one isn't careful. So all this 5.56 vs 223 stuff is silly, to me. I one once naive about it, but then I tried it.

American Eagle 5.56 ammo in a .223 Howa rifle, guess what!? They all fired, and shot well to boot. So there is no for sure yes or no on the issue. Just check out our rifle, and keep an eye on pressure signs. Just as you would for hand loading...
 
Originally Posted By: BearThe 5.56 is loaded to higher chamber pressure than the 223. Usually the 5.56 has a longer throat and a looser chamber to assure proper function on full auto and dirty conditions.Tell them to check the Hornady 7th edition pages 150 through 158 they have the specs. and loads for both,the only diff is slug selection and load pressure.

What you just posted is all chamber difference not round. I've shot hundreds of 556 through 223 rifles.
 
The 5.56 is NOT loaded to higher pressure, the test equipment that SAAMI and the Military use are different, so they get different pressures. It's like checking the air pressure in a tire with two different gauges, one says 50 psi, one says 60 psi. The pressure in the tire is the same, test equiptment is different.

If you read Wiki on the 5.56,

NATO EPVAT test barrels made for 5.56 mm NATO measure chamber pressure at the case mouth, as opposed to the location used by the United States civil standards organization SAAMI. The piezoelectric sensors or transducers NATO and SAAMI use to conduct the actual pressure measurements also differ. This difference in measurement method accounts for upwards of 20,000 psi (140 MPa) difference in pressure measurements. This means the NATO EPVAT maximum service pressure of 430 MPa (62,000 psi) for 5.56 mm NATO, is reduced by SAAMI to 55,000 psi (380 MPa) for .223 Remington.[27] In contrast to SAAMI, the other main civil standards organization C.I.P. defines the maximum service and proof test pressures of the .223 Remington cartridge equal to the 5.56 mm NATO.

The brass in 5.56 is the same as well, same weight, same capacity.
 
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Thousands of shooters have shot thousands of rounds of 5.56 through their .223 guns and vice versa with never a problem. You know why? Because there isn't any!

This pops up a few times a year. It's all hogwash, but it will continue to keep popping up for as long as there are shooters of .223 and 5.56 ammo.
 
Originally Posted By: pahntr760 Each and every chamber is different.

Originally Posted By: pahntr760 American Eagle 5.56 ammo in a .223 Howa rifle, guess what!? They all fired, and shot well to boot. So there is no for sure yes or no on the issue. Just check out our rifle, and keep an eye on pressure signs. Just as you would for hand loading...

Personally, I believe that those 2 statements right there are all you need to know on the subject.

Much the same as it is if you are working up a load in a .243 or any other caliber. There is a very real possibility that your .243 chamber and my .243 chamber will be different. This would be why a max load in your rifle might be too much for mine and necessitates my working up the load slowly.

If there are pressure signs, stop shooting.
 
****, It come up again.
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Originally Posted By: Bear

"The 5.56 is loaded to higher chamber pressure than the 223."



That is not true.

They are the same cases, so they will support the same pressures.

The very last thing in the world the military needs, is US solders dying in combat because their guns are failing because of case failures in combat.

These are all silly wive's tales.

Some people will believe (and repeat) anything.


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CRAP!!! My rifle just blew up because I ran 5.56 in my .223 chamber................



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.....said no one ever.
 
Originally Posted By: pahntr760Oh...and GASP! I use 7.62 brass, resized, in my .243 Winchester chamber...Oh yeah, living on the edge....

Uh, in that case you should weigh the cases, because 7.62 NATO brass is usually quite a bit thicker than .308 Win brass.

Something I've never seen in 5.56 NATO/.223 Rem.

You could end up with a very high pressure .243 round if you weren't aware of that.
 
Originally Posted By: Evil_LurkerOriginally Posted By: pahntr760Oh...and GASP! I use 7.62 brass, resized, in my .243 Winchester chamber...Oh yeah, living on the edge....

Uh, in that case you should weigh the cases, because 7.62 NATO brass is usually quite a bit thicker than .308 Win brass.

Something I've never seen in 5.56 NATO/.223 Rem.

You could end up with a very high pressure .243 round if you weren't aware of that.

Uh... isn't that why we drop 10% and work up.

It makes no difference what cases one uses, ALWAYS drop 10% and work up.

There are many other variables besides case weight that can cause bigger pressure problems than heavy cases.


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Originally Posted By: CatShooterOriginally Posted By: Evil_LurkerOriginally Posted By: pahntr760Oh...and GASP! I use 7.62 brass, resized, in my .243 Winchester chamber...Oh yeah, living on the edge....

Uh, in that case you should weigh the cases, because 7.62 NATO brass is usually quite a bit thicker than .308 Win brass.

Something I've never seen in 5.56 NATO/.223 Rem.

You could end up with a very high pressure .243 round if you weren't aware of that.

Uh... isn't that why we drop 10% and work up.

It makes no difference what cases one uses, ALWAYS drop 10% and work up.

There are many other variables besides case weight that can cause bigger pressure problems than heavy cases.


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You got your proof. Just like the Chuck Norris thing, "because Cat Shoot said so!!!!" The dude appears to know his smoke when it comes to reloading. There is no further need for discussion.
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